Accelerated organoborane initiated polymerizable compositions

ABSTRACT

The invention is a two part polymerizable composition comprising in one part an organoboron compound capable of forming free radical generating species and in the second part one or more compounds capable of free radical polymerization and from about 20 to about 30 parts by weight based on the weight of the second part of i) a halogenated polyolefin having halosulfonyl groups or ii) a mixture of a halogenated polyolefin and an organic sulfonyl halide. The second part may further contain a compound capable of causing the organoboron compound to form free radical generating species upon contacting the two parts. The first part may further comprise one or more compounds capable of free radical polymerization.

BACKGROUND OF THE INVENTION

This invention relates to accelerated polymerizable compositionscomprising compounds containing moieties capable of free radicalpolymerization, organoboron compounds capable of forming free radicalgenerating species capable of initiating free radical polymerization andadhesives based on such compositions. In another embodiment theinvention relates to a method of polymerizing compounds containingmoieties capable of free radical polymerization and to methods ofbonding substrates using such compositions.

Low surface energy olefins such as polyethylene, polypropylene andpolytetrafluroethylene have a variety of attractive properties in avariety of uses, such as toys, automobile parts, furniture applicationsand the like. Because of the low surface energy of these plasticmaterials, it is very difficult to find adhesive compositions that bondto these materials. Adhesives have been developed for bonding to theseplastics. A series of patents issued to Skoultchi, U.S. Pat. Nos.5,106,928; 5,143,884; 5,286,821; 5,310,835 and 5,376,746; Zharov et al.,U.S. Pat. Nos. 5,539,070, 5,690,780 and 5,691,065; Pocius, U.S. Pat. No.5,616,796; U.S. Pat. No. 5,621,143; U.S. Pat. No. 5,681,910; U.S. Pat.No. 5,686,544; U.S. Pat. No. 5,718,977 and U.S. Pat. No. 5,795,657; andSonnenschein et al. U.S. Pat. Nos. 6,806,330; 6,730,759; 6,706,831;6,713,578; 6,713,579 and 6,710,145 (all incorporated herein byreference) disclose polymerizable acrylic compositions which areparticularly useful as adhesives wherein organoboron amine complexes areused to initiate cure. It is disclosed that these complexes are usefulfor initiating polymerization of adhesives which bond to low surfaceenergy substrates.

Many of the disclosed compositions polymerize more slowly than isdesired for use in industrial processes. This results in processes whichexhibit low productivity. Jialanella, U.S. Patent Publication2005-0137370 A1 discloses that the addition of cure accelerators to theabove described compositions wherein the cure accelerators comprisecompounds containing quinone structures; or compounds containing atleast one aromatic ring and at least one, preferably two, substituentson the aromatic ring selected from hydroxyl, ether and both wherein thetwo substituents are located either ortho or para with respect to oneanother, and a compound having a peroxy moiety. The acceleratorsdescribed function well with the disadvantage is that the use of suchcompounds adds an additional component to the formulations. The use ofadditional components adds cost to the formulations.

Therefore, there is a need for adhesive systems that are capable ofbonding to low surface energy substrates which cure rapidly and do notrequire the addition of another component.

SUMMARY OF INVENTION

The invention is a two part polymerizable composition comprising in onepart an organoboron compound capable of forming free radical generatingspecies and in the second part one or more compounds capable of freeradical polymerization and from about 20 to about 30 parts by weightbased on 100 parts of the second part of i) a halogenated polyolefinhaving halosulfonyl groups or ii) a mixture of a halogenated polyolefinand an organic sulfonyl halide. The second part may further contain acompound capable of causing the organoboron compound to form freeradical generating species upon contacting the two parts. The first partmay further comprise one or more compounds capable of free radicalpolymerization. This facilitates formulating compositions that havecommercially desirable volumetric ratios of the two parts. Adhesivecompositions of the present formulation provide excellent adhesion tolow surface energy substrates, such as plastics, and exhibit a fastercuring profile.

The invention is also a method of polymerization comprising contactingthe components of the polymerizable composition under conditions suchthat the polymerizable compounds undergo polymerization. In oneembodiment, the contacting occurs at, or near, ambient temperature. Inanother embodiment, the method further comprises the step of heating thepolymerizable composition to an elevated temperature under conditionssuch that the organoboron compound forms a free radical generatingspecies.

In yet another embodiment the invention is a method of bonding two ormore substrates together which comprises contacting the components ofthe polymerizable composition together under conditions, such thatpolymerization is initiated; contacting the polymerizable compositionwith the two or more substrates; positioning the two or more substrates,such that the polymerizable composition is located between the two ormore substrates; and allowing the polymerizable composition topolymerize and to bond the two or more substrates together. In yetanother embodiment the invention is a method of coating a substratewhich comprises contacting a composition according to the invention withone or more surfaces of a substrate and initiating polymerization of thecomposition according to the invention. In another embodiment theinvention is a laminate comprising two substrates having disposedbetween the substrates and bound to each substrate a compositionaccording to the invention.

The polymerizable compositions of the invention are stable at, or near,ambient temperature and can be cured upon demand by contacting the twoparts of the composition, or alternatively by contacting the two partsof the composition and thereafter heating the compositions above thetemperature at which the organoboron compound forms a free radicalgenerating species. Furthermore, the polymerizable compositions of theinvention can form good bonds to low surface energy substrates withoutthe need for primers or surface treatment, especially at lowtemperatures. The polymerizable compositions of the invention may beformulated to be dispensed in commercial equipment at volume ratios ofthe two parts of 4:1 or less. The polymerized compositions demonstrateexcellent cohesive and adhesive strength at elevated temperatures andthus demonstrate excellent stability at high temperatures. Thepolymerizable compositions of the invention exhibit rapid cure andpreferably exhibit a lap shear strength according to ASTM 03165-91 of 50psi (0.34 mPa) or greater 1 hour after application. Preferably, thepolymerizable compositions demonstrate excellent adhesion to substratesalong with the rapid cure as discussed.

SUMMARY OF FIGURES

FIG. 1 is a graph of the data generated in the Examples.

DETAILED DESCRIPTION OF THE INVENTION

The polymerization initiator is an organoboron containing compound whichis capable of forming a trivalent organoboron compound. In a preferredembodiment, the free radical generating species is a trivalentorganoboron compound. Preferred boron containing compounds aretetravalent in that they have four bonds to the boron of which at leastthree are covalent and one may be covalent or in the form of anelectronic association with a complexing agent. The free radicalgenerating species, such as a trivalent boron compound, is formed whenthe boron containing compound is contacted with another substance,referred to herein as a liberating compound. The free radical generatingspecies generates free radicals by reacting with environmental oxygen.In the embodiment wherein the boron containing compound is tetravalentsuch contacting causes the abstraction of one of the ligands bonded toor complexed to the boron atom to convert it to a trivalent borane. Freeradical generating species is a compound that contains or generates freeradicals under polymerization conditions. The liberating compound can beany compound which reacts with the complexing agent or which abstracts acation from the boron containing compound. Preferably, the boroncontaining compound is an organoborate, an organoboron amine complex oran amido organoborate.

An organoborate is a salt of a positive cation and an anionictetravalent boron. Any organoborate which can be converted to anorganoboron by contact with a decomplexing agent or initiator may beused. One class of preferred organoborates, (also known as quaternaryboron salts) are disclosed in Kneafsey et al., U.S. 2003/0226472 andKneafsey et al., U.S. 2004/0068067, both incorporated herein byreference. Preferred organoborates disclosed in these two U.S. Patentapplications are described by the following formula

wherein

-   R² is C₁-C₁₀ alkyl;-   R³ is independently in each occurrence C₁-C₁₀ alkyl, C₃-C₁₀    cycloalkyl, phenyl, phenyl-substituted C₁-C₁₀ alkyl or phenyl    substituted C₃-C₁₀ cycloalkyl, provided that any two of R² and/or R³    may optionally be part of a carbocyclic ring; and-   M⁺ is a metal ion or a quaternary ammonium ion. Preferred examples    of organoborates include sodium tetraethyl borate, lithium    tetraethyl borate, lithium phenyl triethyl borate and    tetramethylammonium phenyl triethyl borate.

In another embodiment, the organoborate is an internally blocked borateas disclosed in Kendall et al., U.S. Pat. No. 6,630,555, incorporatedherein by reference. Disclosed in this patent are four coordinateinternally blocked borates wherein the boron atom is part of a ringstructure further containing an oxa or thio-moiety. The internallyblocked heterocyclic borates preferably have the following structure:

wherein J is oxygen or sulfur; when J represents oxygen, n is theinteger 2, 3, 4 or 5; when J represents sulfur, n is the integer 1, 2,3, 4 or 5; R⁴, R⁵, R⁶ and R⁷ are independently, substituted orunsubstituted, alkyl or alkylene groups containing 1 to 10 carbon atoms,substituted aryl groups having up to 7 to 12 carbon atoms orunsubstituted aryl groups; R⁵, R⁶ and R⁷ can be hydrogen; R⁴ can be partof a second unsubstituted or substituted cyclic borate; R⁴ can comprisea spiro ring or a spiro-ether ring; R⁴ together with R⁵ can be linked toform a cycloaliphatic ring; or R⁴ together with R⁵ can comprise a cyclicether ring and M in this context, is any positively charged species;with m being a number greater than 0.

The term “internally blocked” in reference to the organoboratesdescribed herein means a four coordinate boron atom being part of aninternal ring structure bridged across two of the four boron coordinatesor valences. Internal blocking includes a single ring or a multi-ringstructure where boron is part of one or multi-ring structures.

In the embodiment where the organoboron compound is in the form of anamine complex, the free radical generating species used in the inventionis a trialkyl borane or an alkyl cycloalkyl borane. The organoboron usedin the complex is a trialkyl borane or an alkyl cycloalkyl borane.Preferably such borane corresponds to the formula:

B—(R¹)₃

wherein B represents Boron; and R¹ is separately in each occurrence aC₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, or two or more of R¹ may combine to forma cycloaliphatic ring. Preferably R¹ is C₁₋₄ alkyl, even more preferablyC₂₋₄ alkyl, and most preferably C₃₋₄ alkyl. Among preferred organoboronsare tri-ethyl borane, tri-isopropyl borane and tri-n-butylborane.

In the embodiment wherein the organoboron compound is an organoboronamine complex, the organoboron is a trivalent organoboron and the aminecan be any amine which complexes reversibly with the organoboron. Suchcomplexes are represented by the formula

wherein R¹ is described hereinbefore and Am is an amine.

The amines used to complex the organoboron compound can be any amine ormixture of amines which complex the organoboron and which can bedecomplexed when exposed to a liberating compound. The desirability ofthe use of a given amine in an amine/organoboron complex can becalculated from the energy difference between the Lewis acid-basecomplex and the sum of energies of the isolated Lewis acid (organoboron)and base (amine) known as binding energy. The more negative the bindingenergy the more stable the complex. Calculation of the binding energyand preferred binding energies are described in Sonnenschein et al.,U.S. Pat. No. 6,706,831 at column 4, lines 36 to 57, incorporated hereinby reference.

Preferred amines include the primary or secondary amines or polyaminescontaining primary or secondary amine groups, or ammonia as disclosed inZharov, U.S. Pat. No. 5,539,070 at column 5, lines 41 to 53,incorporated herein by reference, Skoultchi; U.S. Pat. No. 5,106,928 atcolumn 2, lines 29 to 58, incorporated herein by reference, and Pocius,U.S. Pat. No. 5,686,544 at column 7, line 29 to column 10 line 36,incorporated herein by reference; ethanolamine, secondary dialkyldiamines or polyoxyalkylenepolyamines; and amine terminated reactionproducts of diamines and compounds having two or more groups reactivewith amines as disclosed in Deviny, U.S. Pat. No. 5,883,208 at column 7,line 30 to column 8 line 56, incorporated herein by reference. Withrespect to the reaction products described in Deviny the preferreddiprimary amines include alkyl diprimary amines, aryl diprimary amines,alkyaryl diprimary amines and polyoxyalkylene diamines; and compoundsreactive with amines include compounds which contain two or moremoieties of carboxylic acids, carboxylic acid esters, carboxylic acidhalides, aldehydes, epoxides, alcohols and acrylate groups. Preferredamines described in Deviny include n-octylamine, 1,6-diaminohexane(1,6-hexane diamine), diethylamine, dibutyl amine, diethylene triamine,dipropylene diamine, 1,3-propylene diamine (1,3-propane diamine),1,2-propylene diamine, 1,2-ethane diamine, 1,5-pentane diamine,1,12-dodecanediamine, 2-methyl-1,5-pentane diamine, 3-methyl-1,5-pentanediamine, triethylene tetraamine and diethylene triamine. Preferredpolyoxyalkylene polyamines include polyethyleneoxide diamines,polypropyleneoxide diamines, triethylene glycol propylene diamine,polytetramethyleneoxide diamine andpolyethyleneoxidecopolypropyleneoxide diamines.

In one preferred embodiment, the amine comprises a compound having aprimary amine and one or more hydrogen bond accepting groups, whereinthere are at least two carbon atoms, preferably at least about threecarbon atoms, between the primary amine and hydrogen bond acceptinggroups. Preferably, an alkylene moiety is located between the primaryamine and the hydrogen bond accepting group. Hydrogen bond acceptinggroup means herein a functional group that through either inter- orintramolecular interaction with a hydrogen of the borane-complexingamine increases the electron density of the nitrogen of the amine groupcomplexing with the borane. Preferred hydrogen bond accepting groupsinclude primary amines, secondary amines, tertiary amines, ethers,halogen, polyethers, thioethers and polyamines. Preferred compoundshaving a primary amine and one or more hydrogen bond accepting groupsare described in Sonnenschein et al., U.S. Pat. Nos. 6,730,759, (column4, line 60 to column 5, line 67); Nos. 6,706,831; 6,713,578; 6,713,579and 6,710,145 relevant portions, incorporated herein by reference.

In another embodiment the amine is an aliphatic heterocycle having atleast one nitrogen in the heterocycle. The heterocyclic compound mayalso contain one or more of nitrogen, oxygen, sulfur or double bonds. Inaddition, the heterocycle may comprise multiple rings wherein at leastone of the rings has nitrogen in the ring. Preferable aliphaticheterocyclic amines are described in Sonnenschein et al., U.S. Pat. Nos.6,730,759 (column 6, lines 1 to 45); Nos. 6,706,831; 6,713,578;6,713,579 and 6,710,145 relevant portions, incorporated herein byreference.

In yet another embodiment, the amine which is complexed with theorganoboron is an amidine. Any compound with amidine structure whereinthe amidine has sufficient binding energy as described hereinbefore withthe organoboron, may be used. Preferred amidine compounds are describedin Sonnenschein et al., U.S. Pat. Nos. 6,730,759, (column 6, line 4 tocolumn 7, line 21); 6,706,831; 6,713,578; 6,713,579 and 6,710,145relevant portions, incorporated herein by reference.

In yet another embodiment, the amine that is complexed with theorganoboron is a conjugated imine. Any compound with a conjugated iminestructure, wherein the imine has sufficient binding energy as describedhereinbefore with the organoboron, may be used. The conjugated imine canbe a straight or branched chain imine or a cyclic imine. Preferred iminecompounds are described in Sonnenschein et al., U.S. Pat. Nos. 6,730,759(column 7, line 22 to column 8, line 24); 6,706,831; 6,713,578;6,713,579 and 6,710,145 relevant portions, incorporated herein byreference.

In another embodiment the amine can be an alicyclic compound havingbound to the alicyclic ring a substituent containing an amine moiety.The amine containing alicyclic compound may have a second substituentthat contains one or more nitrogen, oxygen, sulfur atoms or a doublebond. The alicyclic ring can contain one or two double bonds. Thealicyclic compound may be a single or multiple ring structure.Preferably the amine on the first substituent is primary or secondary.Preferably, the alicyclic ring is a 5 or 6 membered ring. Preferablyfunctional groups on the second substituent are amines, ethers,thioethers or halogens. Preferred alicyclic compound with one or moreamines containing substituents are described in Sonnenschein et al.,U.S. Pat. Nos. 6,730,759 (column 8, line 25 to line 59); No. 6,706,831;6,713,578; 6,713,579 and 6,710,145 relevant portions, incorporatedherein by reference.

In another preferred embodiment the amine further contains siloxane,that is, an amino siloxane. Any compound with both amine and siloxaneunits wherein the amine has sufficient binding energy as describedhereinbefore with the organoboron, may be used. Preferred amines withsiloxane moieties are further described in U.S. Pat. No. 6,777,512, andtitled AMINE ORGANOBORANE COMPLEX INITIATED POLYMERIZABLE COMPOSITIONSCONTAINING SILOXANE POLYMERIZABLE COMPONENTS, (column 10, line 14 tocolumn 11, line 29, incorporated herein by reference).

In the embodiment where the organoboron compound is an organoboron aminecomplex, the equivalent ratio of amine compound(s) to borane compound inthe complex is relatively important. An excess of amine is preferred toenhance the stability of the complex and in the embodiment where theliberating compound is an isocyanate functional compound to react withthe isocyanate functional compound thereby resulting in the presence ofpolyurea in the final product. The presence of polyurea improves thehigh temperature properties of the composition. In one embodiment theorganoboron compound is an amido-borate comprising a tetravalent boronanion wherein the boron atom is bound to a nitrogen compound eithercovalently or ionically. The amido-borate comprises one or moreamido-borate anions and one or more corresponding cations whichneutralize the amido-borate anion. A borate is a salt of a positivecation and an anionic tetravalent boron. The amido-borates areorganoborates wherein one of the ligands on the boron atom is thenitrogen of ammonia or an organic compound which contains a nitrogenatom and which may contain a heteroatom or a heteroatom containingfunctional moieties wherein the nitrogen may be quaternary and cationic.In some embodiments, the cation can be the nitrogen bonded to the boronin the form of a quaternary nitrogen. This is especially true where thenitrogen compound used to form the amido-borate has more than onenitrogen which is bonded to more than one boron atoms of organoboranesto form the amido-borate. The organoborane bonded to the nitrogen atomto form the amido-borate comprises a boron atom with three bonds tohydrocarbyl moieties wherein the hydrocarbyl moieties may furthercomprise one or more heteroatoms or heteroatom containing functionalgroups which do not interfere in the described function of theamido-borate compounds. Preferred heteroatoms which may be present inhydrocarbyl moieties described herein include oxygen, sulfur, nitrogen,silicon, halogens, and the like with oxygen being most preferred.Preferred heteroatom containing functional groups which may be presentas part of hydrocarbyl moieties as described herein include ethers,thioethers, amines, silanes, siloxanes and the like with ethers beingmost preferred. The boron atom may be bonded to three separatehydrocarbyl moieties or may be bonded to two hydrocarbyl moietieswherein one hydrocarbyl moiety has two bonds to the boron atom therebyforming one or more cyclic ring(s). The organoborane used to prepare theamido-borate is preferably a trialkyl borane or an alkyl cycloalkylborane.

In one embodiment the amido-borate is a compound comprising one or moretetravalent boron anions and one or more of: i) an organic compoundcontaining a nitrogen atom and a cation or ii) an ammonium cation;wherein the each of the one or more tetravalent boron atoms is bonded tothe nitrogen atom of an ammonium cation or an organic compoundcontaining a nitrogen atom. In another embodiment the amido-boratecomprises two or more tetravalent boron anions wherein at least one ofthe borates anions is bonded to the nitrogen atom of an organiccompound; and at least one of the borate anions is bonded to thenitrogen of an ammonium cation; and one or more additional cationswherein the number of additional cations is the same as the number oftetravalent boron atoms bonded to the nitrogen atom of an organiccompounds containing at least one nitrogen atom.

The nitrogen containing portion of the amido-borate may be derived fromammonia or any organic compound containing a nitrogen atom which iscapable of bonding to boron and is preferably derived from ammonia, ahydrocarbyl amine or a polyamine. The nitrogen atoms of such compoundsbonded to the boron atoms to form the borates can be primary, secondary,or quaternary, preferably secondary or tertiary or quaternary. Inanother preferred embodiment the nitrogen atom bonded to theorganoborane to prepare the amido-borate is a nitrogen located in or onthe ring of a heteroaromatic cyclic compound. In those embodiments wherethe nitrogen is quaternary, the quaternary nitrogen portion of theamido-borate is the cationic counterion for the borate anion portion ofthe compound to which the quaternary nitrogen atom is bonded. Thehydrocarbyl amine or polyamine and the nitrogen containing aromaticheterocylic compound may contain heteroatoms as described hereinbeforeor be further substituted with substituents which do not interfere withthe functioning of such compounds in the compositions of the inventionas described hereinbefore. The hydrocarbyl amines preferably correspondto the formula

H_(2-r)-N-(R⁸)_(r)

wherein R⁸ is independently in each occurrence an alkyl, cycloalkyl,aryl, alkaryl, or aralkyl group; wherein such group may optionallycontain one or more heteroatoms, one or more heteroatom containingfunctional groups, as described hereinbefore, or a proton.

-   R⁸ is preferably C₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, C₆₋₁₂ aryl, C₇₋₂₀    alkaryl or C₇₋₂₀ aralkyl; wherein such group may optionally contain    one or more heteroatoms of O or S, preferably O, or one or more O or    S containing heteroatom functional moieties. R⁸ is more preferably    C₁₋₄ alkyl or C₁₋₁₀ alkoxyalkyl; even more preferably methyl, ethyl,    propyl, methoxypropyl, ethoxypropyl or propoxypropyl. In reference    to alkoxyalkyl, the number of carbon atoms refers to the total    carbon atoms in the moiety. The hydrocarbyl polyamines preferably    correspond to the formula

wherein R⁸ is as described hereinbefore;

-   R⁹ is independently in each occurrence a divalent hydrocarbyl moiety    which may contain one or more heteroatoms or one or more heteroatom    containing functional moieties as described hereinbefore;-   r is independently in each occurrence 0, 1 or 2; and-   q is independently in each occurrence 1 or 2.

The aromatic nitrogen containing heterocyclic compounds preferablycorrespond to the formula

wherein R¹⁰ is independently in each occurrence hydrogen, an alkyl, analkoxyl, aralkyl or an aryl group; wherein such group may optionallycontain one or more heteroatoms, one or more heteroatom containingfunctional moieties, as described hereinbefore, or a proton; Z isindependently in each occurrence N, Si, P or C and w is 0 or 1 with theproviso that where Z is N or P, w can only be 0, whereas when Z is C orSi; w can only be 1. Preferably Z is N or C. R¹⁰ is preferably hydrogen,C₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, C₆₋₁₂ aryl, C₇₋₂₀ alkaryl or C₇₋₂₀aralkyl; wherein such group may optionally contain one or moreheteroatoms of O or S, preferably O, or one or more O or S heteroatomcontaining functional moieties. R³ is more preferably hydrogen, C₁₋₄alkyl or a C₁₋₁₀ alkoxyalkyl even more preferably hydrogen, methyl,ethyl, propyl and most preferably hydrogen. Preferably R⁹ isindependently in each occurrence C₂₋₂₀ alkylene, C₃₋₂₀ cycloalkylene,C₆₋₂₀ arylene, C₇₋₂₀ alkarylene or C₇₋₂₀ aralkylene; optionallycontaining one or more heteroatoms or heteroatom containing functionalmoieties; preferably C₂₋₂₀ alkylene or C₂₋₂₀ alkylene groups containingone or more oxygen atoms; and even more preferably C₂₋₄ alkylene.Preferred heteroatoms are O or S, with 0Omost preferred.

The cation which forms the salt with the amido-borate can be any cationwhich forms a salt with the amido-borate. The cation can be any group IAand group IIA metal, any inorganic cation or organic cation. Preferably,the cation is an onium ion or an alkali metal ion. More preferably thecation is sodium, potassium, a phosphonium or an ammonium ion. Preferredammonium ions are tetraalkyl ammonium ions, with tetramethyl ammoniumion being most preferred. Preferred phosphonium ions are tetraalkylphosphonium or tetraaryl phosphonium; with tetrabutyl phosphonium andtetraphenyl phosphonium preferred.

The amido-borates preferably correspond to one of the formulas:

wherein R¹, R⁸, R⁹, R¹⁰ and w are as described hereinbefore;

-   X is independently in each occurrence a cation;-   p is independently in each occurrence 0 or 1;-   q is independently in each occurrence 1 or 2 wherein q is 2. The    nitrogen atom is the cation counter-balancing the borate anion;-   with the proviso that the sum of p and q on each linked boron and    nitrogen pair is 2; and the sum of the p is 1 or 2. Where q is 2,    the nitrogen to which it is bonded is quaternary and carries a    positive charge which balances the negative charge found on the    boron of the borate and a cation is not needed to neutralize the    borate.

Preferably, X is independently in each occurrence an onium or an alkalimetal ion; more preferably X is an ammonium, phosphonium, potassium orsodium cation; even more preferably X is a tetraalkyl ammonium,tetraalkyl phosphonium, tetraaryl phosphonium or sodium and mostpreferably X is tetramethyl ammonium, tetrabutyl ammonium, tetrabutylphosphonium or tetraphenyl phosphonium.

In another embodiment the cationic species can have more than onecationic species that form salts with the borate anions. Thus, thecationic species can form a salt with more than one borate species.Preferably, the cationic species with more than one cation have 2 to 4,preferably 2 or 3 cations and even more preferably 2. Among preferredcationic species having more than one cation are compounds having 2 ormore ammonium or phosphonium cations, with compounds having two ammoniumcations being preferred. Examples of such compounds include1,2(di(trimethylammonium)) ethane. In the embodiment where the cationicspecies have more than one cation, the amido-borates preferablycorrespond to the formulas:

wherein R¹, R⁸, R⁹, R¹⁰, w, X, p and q are as described hereinbefore;

-   R¹¹ is independently in each occurrence a t-valent hydrocarbyl group    optionally containing one or more heteroatoms or heteroatom    containing functional moieties as described hereinbefore;-   Y is independently in each occurrence

-   t is independently in each occurrence 2 or greater. Preferably, t is    2 to 4, even more preferably 2 or 3 and most preferably 2.-   Preferably R¹¹ is independently in each occurrence a t-valent C₂₋₂₀    alkylene; C₃₋₂₀ cycloalkylene; C₆₋₂₀ arylene; C₇₋₂₀ alkarylene; or    C₇₋₂₀ aralkylene optionally containing one or more heteroatoms or    heteroatom containing functional moieties, preferred heteroatoms are    sulfur and oxygen with oxygen most preferred. More preferably R¹¹ is    a t-valent alkylene group, and more preferably a t-valent C₂₋₆    alkylene group. Most preferably R¹¹ is a divalent C₂₋₄ alkylene    group.

The amido-borates can be prepared from the base amines described above,such amines are commercially available. The amine can be contacted witha base, in a solvent and no solvent if the amine is liquid, resulting ina salt. Inert organic solvents such as tetrahydrofuran may be used. Asalt of the amine and the cation from the base is formed. The resultingsalt is contacted with a trivalent organoborane to form theamido-borate. The contacting is preferably performed in a vacuum orunder an inert atmosphere. Preferably, the process is performed atambient temperatures. If a solvent is used, it can be removed in vacuo.

The amido-borate is capable of forming a trivalent organoboron compound.The amido-borates are tetravalent in that they have four bonds to theboron. The free radical generating species, the trivalent boroncompound, is formed when the amido-borate is contacted with a liberatingcompound. The trivalent borane generates free radicals by reacting withenvironmental oxygen. The nitrogen containing portion of theamido-borate is preferably derived from ammonia, a hydrocarbyl amine ora polyamine. The nitrogen atoms of such compounds bonded to the boronatoms to form the borates can be primary, secondary or tertiary,preferably secondary or tertiary. In another embodiment the nitrogenatom bonded to the organoborane to prepare the amido-borate is anitrogen located in or on the ring of a heteroaromatic cyclic compound.The nitrogen atom bonded to the boron atom can be primary, secondary,tertiary or quaternary. In those embodiments where the nitrogen isquaternary, the quaternary nitrogen portion of the amido-borate is thecationic counterion for the borate anion portion of the compound towhich the quaternary nitrogen atom is bonded. The hydrocarbyl amine orpolyamine and the nitrogen containing aromatic heterocylic compound maycontain heteroatoms or be further substituted with substituents which donot interfere with the functioning of such compounds in the compositionsof the invention. The hydrocarbyl amines preferably correspond to theformula

H_(2-r)-N-(R⁸)_(r)

wherein R⁸ is independently in each occurrence an alkyl, cycloalkyl,aryl, alkaryl, or aralkyl group; wherein such group may optionallycontain a heteroatom, a heteroatom containing functional group or aproton. The hydrocarbyl polyamines preferably correspond to the formula

wherein R⁸ is as described hereinbefore;

-   R⁹ is independently in each occurrence a divalent hydrocarbyl    moiety;-   r is independently in each occurrence 0, 1 or 2; and-   q is independently in each occurrence 1 or 2.-   The aromatic nitrogen containing heterocyclic compounds preferably    correspond to the formula

wherein R¹⁰ is independently in each occurrence hydrogen, an alkyl or anaryl group; wherein such group may optionally containing a heteroatom, aheteroatom containing functional group or a proton; Z is independentlyin each occurrence N, Si, P or C and w is 0 or 1 with the proviso thatwhere Z is N or P, w can only be 1, whereas when Z is C or Si; w can be1 or 2.

The organoboron compounds capable of generating free radical generatingspecies are used in the polymerizable compositions of the invention inan amount sufficient to initiate polymerization when the trivalentorganoboron is liberated and to facilitate bonding of the polymerizablecompositions where desired. Preferably, the organoboron compound ispresent in polymerizable compositions in an amount of about 0.1 part byweight based on 100 parts by weight of the composition or greater, morepreferably about 0.5 parts by weight or greater and most preferablyabout 1 part by weight or greater. Preferably, the amido-borate ispresent in polymerizable compositions in an amount of about 30 parts byweight or less based on 100 parts by weight of the composition, morepreferably about 20 parts by weight or less and most preferably about 10parts by weight or less.

Compounds capable of free radical polymerization which may be used inthe polymerizable compositions of the invention include any monomers,oligomers, polymers or mixtures thereof which contain olefinicunsaturation which can polymerize by free radical polymerization. Suchcompounds are well known to those skilled in the art. Mottus, U.S. Pat.No. 3,275,611, provides a description of such compounds at column 2,line 46 to column 4, line 16, incorporated herein by reference.Preferred classes of compounds containing olefinic unsaturation areSonnenschein et al., U.S. Pat. Nos. 6,730,759 (column 9, line 7 to line54); No. 6,706,831; 6,713,578; 6,713,579 and 6,710,145 relevantportions, incorporated herein by reference. Examples of preferableacrylates and methacrylates are disclosed in Skoultchi, U.S. Pat. No.5,286,821 at column 3, line 50 to column 6, line 12, incorporated hereinby reference and Pocius, U.S. Pat. No. 5,681,910 at column 9, line 28 tocolumn 12, line 25, incorporated herein by reference. Also useful inthese compositions are acrylate crosslinking molecules includingethylene glycol dimethacrylate, ethylene glycol diacrylate,triethyleneglycol dimethacrylate, diethylene glycol bismethacryloxycarbonate, polyethylene glycol diacrylate, tetraethylene glycoldimethacrylate, diglycerol diacrylate, diethylene glycol dimethacrylate,pentaerythritol triacrylate, trimethylolpropane trimethacrylate,isobomylmethacrylate and tetrahydrofurfuryl methacrylate. In theembodiment where the composition is used as an adhesive, acrylate and/ormethacrylate based compounds are preferably used as the compoundscapable of free radical polymerization. The most preferred acrylate andmethacrylate compounds include methylmethacrylate, butylmethacrylate,2-ethylhexylmethacrylate, and cyclohexylmethylmethacrylate.

Preferred amounts of compounds capable of free radical polymerizationare preferably about 10 parts by weight or greater based on 100 parts ofthe total polymerizable composition, more preferably about 20 parts byweight or greater and most preferably about 30 parts by weight orgreater. Preferred amounts of compounds capable of free radicalpolymerization are preferably about 90 parts by weight or less based on100 parts by weight of the polymerizable composition, more preferablyabout 85 parts by weight or less and most preferably about 80 parts byweight or less.

In another embodiment, the compositions of the invention include twopart polymerizable compositions comprising in one part an organoboroncompound and one or more compounds containing one or more ring openingheterocyclic moieties, and in a second part, compounds capable of beingpolymerized by free radical polymerization, a catalyst capable ofpolymerizing compounds containing ring opening heterocyclic moieties, ahalogenated polyolefin having halosulfonyl groups or a mixture of ahalopolyolefin and an organic sulfonyl compound and, optionally, acomponent that will cause the organoboron compound to form a freeradical generating species. In one embodiment the invention is a twophase system comprising a first phase containing one or more polymersprepared from the compounds which polymerize by free radicalpolymerization and a second phase comprising polymerized or partiallypolymerized compounds derived from one or more compounds containing ringopening heterocyclic moieties. Such polymerizable compositions and thepolymers resulting from such compositions are described in Sonnenscheinet al., U.S. Pat. No. 6,762,260 relevant compositions incorporatedherein by reference. The compound containing a heterocyclic ring openingmoiety can be any monomer, oligomer or prepolymer containing aheterocyclic moiety capable of ring opening and polymerization. Theheteroatom in the heterocyclic moiety is preferably nitrogen, oxygen orsulfur, with nitrogen and oxygen being preferred and oxygen being mostpreferred. Preferably the heterocyclic moiety is a 3 membered ring.Preferred heterocyclic moieties are oxirane and aziridine moieties, withoxirane moieties being most preferred. Preferred heterocyclic ringopening compounds are further described in Sonnenschein et al., U.S.Pat. No. 6,762,260 (column 10, line 34 to column 11, line 22),incorporated herein by reference. The polymerizable formulation maycontain about 2 parts by weight or greater of heterocyclic polymerizablecompound based on 100 parts by weight of the polymerizable composition;more preferably about 5 parts by weight or greater and most preferredabout 10 parts by weight or greater. The polymerizable formulation maycontain about 50 parts by weight or less based on 100 parts by weight ofthe polymerizable composition, more preferably about 45 parts by weightor less and most preferably about 40 parts by weight or less ofheterocyclic polymerizable compound. In some cases it may be useful tocrosslink the free radical polymerizable compound phase to theheterocyclic ring opening polymerizable compound derived phase asdescribed in Sonnenschein et al, U.S. Pat. No. 6,762,260 (column 11,line 53 to column 1, line 11), incorporated herein by reference. Theamount of crosslinker used is that amount which gives the desiredproperties, that is, sufficient lap shear strength at 125° C. or above,yet does not cause the room temperature adhesive strength to go belowthe desired value as defined herein. Preferred amounts of crosslinkerare about 0 part by weight or greater based on 100 weight parts of thepolymerizable formulation, more preferably about 1 part by weight orgreater; even more preferably about 3 parts by weight or greater andmost preferably about 5 parts by weight or greater. Preferably theamount of crosslinker used is about 20 parts by weight or less based on100 weight parts of the total polymerizable formulation; even morepreferably about 15 parts by weight or less and most preferably about 12parts by weight or less.

In one embodiment the invention of the polymerizable compositions mayfurther comprise one or more compounds, oligomers or prepolymers havinga siloxane backbone and reactive moieties capable of polymerization, acatalyst for the polymerization of the one or more compounds, oligomersor prepolymers having a siloxane backbone and reactive moieties capableof polymerization as disclosed in U.S. Pat. No. 6,777,512, titled AMINEORGANOBORANE COMPLEX INITIATED POLYMERIZABLE COMPOSITIONS CONTAININGSILOXANE POLYMERIZABLE COMPONENTS (column 12, line 66 to column 15, line54).

The organoboron compounds useful for polymerization of the compoundshaving moieties capable of free radical polymerization may be convertedto compounds capable of forming free radical generating species by theapplication of a liberating compound, sometimes referred to as adecomplexation agent, that will cause the formation of compounds capableof forming free radical generating species, such as a trivalent boranecompound, such as by displacing the amine from the borane.

The displacement of the amine from the alkylborane or the liberation ofthe trialkyl borane from the borate structure can occur with anychemical for which the exchange energy is favorable, such as mineralacids, organic acids, Lewis acids, isocyanates, acid chlorides,sulphonyl chlorides, aldehydes, and the like. Preferred liberatingcompounds are acids and isocyanates. In those embodiments where theinitiator for the ring opening polymerization is a Lewis acid, theliberating compound may be omitted as Lewis acids may also function asthe liberating compound. If the Lewis acid is used as the heterocyclicring opening polymerization initiator no additional amounts are neededover those amounts needed to initiate polymerization to also function asthe liberating compound. Polymerization may also be initiated thermally.The temperature at which the composition is heated to initiatepolymerization is dictated by the binding energy of the complex orcompound containing the organoborane. Generally the temperature used toinitiate the polymerization by liberating the trialkyl borane is about30° C. or greater and preferably about 50° C. or greater. Preferably thetemperature at which thermally initiated polymerization is initiated isabout 120° C. or less and more preferably about 100° C. or less. Anyheat source that heats the composition to the desired temperature can beused, provided the heat source does not negatively impact the componentsof the composition or its function. In this manner the composition maybe contacted with the substrates either before or after the compositionis exposed to heat. If the composition is heated prior to contact withthe substrates, the composition should be contacted with the substratesbefore the composition has polymerized to the point at which thecomposition is no longer able to adhere to the substrates. It may benecessary in the thermally initiated reaction to control the oxygencontent such that there is adequate oxygen to create favorableconditions for radical formation but not so much as to inhibit thepolymerization.

The compositions of the invention may further contain a stabilizingamount of a dihydrocarbyl hydroxyl amine. Stabilizing as used hereinrefers to preventing polymerization until desired. Generally this meansthat polymerization is inhibited under normal storage conditions. Normalstorage conditions mean storage at a temperature of about 0° C. to about40° C., wherein the adhesive is stored in a sealed container. A stablecomposition is one that does not experience undesired viscosity growthduring a defined period. Viscosity growth is evidence of polymerizationof the monomers present. In a preferred embodiment, a composition isstable if the viscosity does not increase more than 150 percent over atime period of 30 days when stored at temperatures of 40° C. or less,more preferably 100 percent or less over a time period of 30 days andmost preferably 50 percent or less over a time period of 30 days.

Dihydrocarbyl hydroxyl amines useful herein include any such compoundswhich when included in the compositions of this invention improve thestability of the compositions as described herein. Preferreddihydrocarbyl amines correspond to the formula (R¹¹)₂ N—OH wherein R¹¹is independently in each occurrence a hydrocarbyl moiety. Preferably R¹¹is independently in each occurrence a C₂₋₃₀ alkyl, alkaryl or arylmoiety; more preferably a C₁₀₋₂₀ alkyl, alkaryl or aryl moiety; withC₁₀₋₂₀ alkyl moieties being even more preferred. Among preferreddihydrocarbyl hydroxyl amines are hydroxylamine freebase from BASF,hydroxylamine derivatives from Mitsui Chemicals America, Inc. andIRGASTAB™ FS Products from Ciba Specialty Chemicals which containsoxidized bis(hydrogenate tallow alkyl) amine also described asbis(N-dodecyl) N-hydroxyl amine. The dihydrocarbyl hydroxyl amines areutilized in sufficient amounts to stabilize the compositions of theinvention. Preferably the dihydrocarbyl hydroxyl amines are used in anamount of about 1 part per million by weight of the compositions of theinvention or greater, more preferably about 2 parts per million orgreater and most preferably about 5 parts per million or greater.Preferably the dihydrocarbyl hydroxyl amines are used in an amount ofabout 100,000 parts per million by weight of the compositions of theinvention or less, more preferably about 50,000 parts per million orless, even more preferably about 10,000 parts per million or less andmost preferably about 3,000 parts per million or less.

The compositions of the invention further comprise an accelerator forthe cure of the polymerizable compositions. The accelerator is ahalosulfonated halopolyolefin or a mixture of a halopolyolefin and anorganic sulfonyl halide. Halopolyolefin means herein a polyolefin whichis substituted with halogen atoms. Polyolefin as used herein refers topolymers derived from one or more compounds having carbon chains withunsaturation in the backbone where the polymerization occurs through theunsaturated sites of the compounds. Any halogenated polyolefin whichdonates electrons to the organoboron compound can be used. Preferredhalogenated polyolefins are halogenated polyethylenes and halogenatedpolypropylenes or copolymers containing halogenated polyethylene orhalogenated polypropylene segments. Preferably the halogenatedpolyolefins have sufficient elastomeric nature to improve the ductilityof the polymerized composition of the invention. Preferred halogens onthe polyolefins are fluorine and chlorine with chlorine most preferred.The halogenated polyolefins preferably have a halogen content of about20 percent by weight or greater and more preferably about 25 percent byweight or greater. The halogenated polyolefins preferably have a halogencontent of about 50 percent by weight or less and more preferably about45 percent by weight or less and most preferably 40 percent by weight orless. In a most preferred embodiment the halogenated polyolefin isfurther substituted with sulfonyl halide groups. Preferred halides onthe sulfonyl halides are fluorine and chlorine, with chlorine mostpreferred. Preferred halosulfonated halopolyolefins include HYPALON™H-20, H-30, H-40, H-405, H-4085, H-48, HPG6525, Acsium, HPR 6983, CP,CPR 6140 and CP 337 chlorosulfonated chlorinated polyethylenes availablefrom DuPont Performance Elastomers (HYPALON is a trademark of DuPont).

In another embodiment halopolyolefins which do not contain halosulfonylgroups may be used in conjunction with organic sulfonyl halides. Anyorganic sulfonyl halides which in conjunction with a halogenatedpolyolefin accelerate the cure of the polymerizable compositions of theinvention may be used. Preferable sulfonyl chlorides include mono- orpolyfunctional and can be C₁-C₁₂ alkyl sulfonyl chlorides, such asmethane or butane sulfonyl chloride, C₆-C₂₄ aromatic sulfonyl chlorides,such as benzene or toluene sulfonyl chloride. Some sulfonyl chloridescontaining hetero atoms have also been found to work, such asdiphenylether-4,4′-disulfonyl chloride.

The halosulfonyl groups are preferably present in the form ofsubstituents on the polyolefin or as a sulfonyl halide in sufficientamounts to provide about 0.1 grams of sulfur content or greater per 100grams of halogenated polyolefin and more preferably about 0.5 grams orgreater of sulfur per 100 grams of halogenated polyolefin. Thehalosulfonyl groups are preferably present in the form of substituentson the polyolefin or as a sulfonyl halide in sufficient amounts toprovide 1.5 sulfur grams of content or less by per 100 grams ofhalogenated polyolefin and more preferably about 1.0 grams of sulfur orless per 100 grams of halogenated polyolefin. The halosulfonatedhalogenated polyolefin or composition of halogenated polyolefin andorganic sulfonyl halide are present in a sufficient amount to increasethe speed of cure of the polymerizable compositions of the invention.Preferably such compositions are present in an amount of about 20 partsby weight or greater based on 100 parts of the second part. Preferablysuch compositions are present in an amount of about 30 parts by weightor less of the second part and more preferably about 25 parts by weightor less.

Preferably, the accelerator is located in the part that does not containthe organoboron compound. Often the part containing the organoboroncompound is referred to as the hardener side, and the other part isreferred to as the resin side because the largest part of thepolymerizable compound is found in this part. Hydrocarbyl as used hereinmeans any moiety having both carbon and hydrogen atoms and includessaturated and unsaturated, branched and unbranched, hydrocarbon chainsand/or ring structures. Alkyl refers to branched and unbranchedsaturated hydrocarbon chains. Alkenyl refers to branched and unbranchedunsaturated hydrocarbon chains. Aryl means an aromatic hydrocarbonmoiety. Alkaryl means an aromatic hydrocarbon moiety with a straight orbranched hydrocarbon chain attached. Aralkyl means a straight orbranched hydrocarbon chain with an aryl group attached. Acyl means ahydrocarbyl and carbonyl moiety. Unless otherwise stated these moietiesmay be substituted with any other substituent which does notsignificantly interfere in the function of the compound to which themoiety is attached or bonded.

The two-part polymerizable compositions or adhesive compositions of theinvention are uniquely suited for use with conventional, commerciallyavailable dispensing equipment for two-part compositions. Once the two-parts have been combined, the composition should be used quickly, as theuseful pot life (open time) may be short depending upon the monomer mix,the amount of organoboron compound, the amount of catalyst and thetemperature at which the bonding is performed. The adhesive compositionsof the invention are applied to one or both substrates and then thesubstrates are joined together, preferably with pressure to force excesscomposition out of the bond line. In general, the bonds should be madeshortly after the composition has been applied, preferably within about10 minutes. The typical bond line thickness is about 0.005 inches (0.13mm) to about 0.03 inches (0.76 mm). The bond line can be thicker if gapfilling is needed as the composition of the invention can function asboth an adhesive and a gap filler. The bonding process can easily becarried out at room temperature and to improve the degree of bonding, itis desirable to keep the temperature below about 40° C., preferablybelow about 30° C., and most preferably below about 25° C.

The compositions may further comprise a variety of optional additives.One particularly useful additive is a thickener such as medium to high(about 10,000 to about 1,000,000) molecular weight polymethylmethacrylate which may be incorporated in an amount of about 10 to about60 weight parts, based on 100 parts by weight of the composition.Thickeners may be employed to increase the viscosity of the compositionto facilitate application of the composition.

Another particularly useful additive is an elastomeric material. Thematerials may improve the fracture toughness of compositions madetherewith which can be beneficial when, for example, bonding stiff, highyield strength materials such as metal substrates that do notmechanically absorb energy as easily as other materials, such asflexible polymeric substrates. Such additives can be incorporated in anamount of about 5 parts to about 35 parts by weight, based on 100 partsby weight of the composition. Useful elastomeric modifiers include thechlorinated or chlorosulphonated polyethylenes used as acceleratorsherein such as HYPALON™ 30 (commercially available from E. I. Dupont deNemours & Co., Wilmington, Del.) and block copolymers of styrene andconjugated dienes (commercially available from Dexco Polymers under thetrademark VECTOR, and Firestone under the trademark STEREON). Alsouseful, and even more preferred, are certain graft copolymer resins suchas particles that comprise rubber or rubber-like cores or networks thatare surrounded by relatively hard shells, these materials often beingreferred to as “core-shell” polymers. Most preferred are theacrylonitrile-butadiene-styrene graft copolymers available from Rohm andHaas. In addition to improving the fracture toughness of thecomposition, core-shell polymers can also impart enhanced spreading andflow properties to the uncured composition. These enhanced propertiesmay be manifested by a reduced tendency for the composition to leave anundesirable “string” upon dispensing from a syringe-type applicator, orsag or slump after having been applied to a vertical surface. Use ofmore than about 20 parts by weight based on 100 parts by weight of thepolymerizable composition of a core-shell polymer additive is desirablefor achieving improved sag- slump resistance. Generally the amount oftoughening polymer used is that amount which gives the desired toughnessto the polymer or the adhesive prepared.

Polymerizable compositions according to the invention may be used inwide variety of ways, including as adhesives, coatings, primers, tomodify the surface of polymers, and injection molding resins. They mayalso be used as matrix resins in conjunction with glass and metal fibermats such as in resin transfer molding operations. They may further beused as encapsulants and potting compounds such as in the manufacture ofelectrical components, printed circuit boards and the like. Quitedesirably, they provide polymerizable adhesive compositions that canbond a wide range of substrates, including polymers, wood, ceramics,concrete, glass and primed metals. Another desirable related applicationis their use in promoting adhesion of paints to low surface energysubstrates such as polyethylene, polypropylene,polyethyleneterephthalate, polyamides, and polytetrafluoroethylene, andtheir co-polymers. In this embodiment the composition is coated onto thesurface of the substrate to modify the surface to enhance the adhesionof the final coating to the surface of the substrate.

The compositions of the invention can be used in coating applications.In such applications the composition may further comprise a carrier suchas a solvent. The coating may further contain additives well known tothose skilled in the art for use in coatings, such as pigments to colorthe coating, inhibitors and UV stabilizers. The compositions may also beapplied as powder coatings and may contain the additives well known tothose skilled in the art for use in powder coatings.

The compositions of the invention can also be used to modify the surfaceof a polymeric molded part, extruded film or contoured object.Compositions of the invention can also be used to change thefunctionality of a polymer particle by surface grafting of polymerchains on to the unmodified plastic substrate.

Polymerizable compositions of the invention are especially useful foradhesively bonding low surface energy plastic or polymeric substratesthat historically have been very difficult to bond without usingcomplicated surface preparation techniques, priming, etc. By low surfaceenergy substrates is meant materials that have a surface energy of about45 mJ/m² or less, more preferably about 40 mJ/m² or less and mostpreferably about 35 mJ/m² or less. Included among such materials arepolyethylene, polypropylene, acrylonitrile-butadiene-styrene,polyamides, syndiotactic polystyrene, olefin containing blockco-polymers, and fluorinated polymers such as polytetrafluoroethylene(TEFLON™) which has a surface energy of less than about 20 mJ/m². (Theexpression “surface energy” is often used synonymously with “criticalwetting tension” by others.) Other polymers of somewhat higher surfaceenergy that may be usefully bonded with the compositions of theinvention include polycarbonate, polymethylmethacrylate, andpolyvinylchloride.

The polymerizable compositions of the invention can be easily used astwo-part adhesives. The components of the polymerizable compositions areblended as would normally be done when working with such materials. Theliberating compound for the organoboron compound is usually includedwith the olefinic, polymerizable component so as to separate it from theorganoboron compound, thus providing one-part of the two-partcomposition. The organoboron compounds of the polymerization initiatorsystem provides the second part of the composition and is added to thefirst part shortly before it is desired to use the composition.Similarly, the Lewis acid catalyst where used for the heterocyclic ringopening compound polymerization is kept separate from the heterocyclicring opening compound. The Lewis acid catalyst may be added to the firstpart directly or it may be pre-dissolved in an appropriate carrier suchas a reactive olefinic monomer, i.e., methyl methacrylate or a MMA/PMMAviscous solution.

For a two-part adhesive such as those of the invention to be most easilyused in commercial and industrial environments, the volume ratio atwhich the two-parts are combined should be a convenient whole number.This facilitates application of the adhesive with conventional,commercially available dispensers. Such dispensers are shown in U.S.Pat. Nos. 4,538,920 and 5,082,147 (incorporated herein by reference) andare available from Conprotec, Inc. (Salem, N.J.) under the trade nameMIXPAC. Typically, these dispensers use a pair of tubular receptaclesarranged side-by-side with each tube being intended to receive one ofthe two-parts of the adhesive. Two plungers, one for each tube, aresimultaneously advanced (e.g., manually or by a hand-actuated ratchetingmechanism) to evacuate the contents of the tubes into a common, hollow,elongated mixing chamber that may also contain a static mixer tofacilitate blending of the two-parts. The blended adhesive is extrudedfrom the mixing chamber onto a substrate. Once the tubes have beenemptied, they can be replaced with fresh tubes and the applicationprocess continued. The ratio at which the two-parts of the adhesive arecombined is controlled by the diameter of the tubes. (Each plunger issized to be received within a tube of fixed diameter, and the plungersare advanced into the tubes at the same speed.) A single dispenser isoften intended for use with a variety of different two-part adhesivesand the plungers are sized to deliver the two-parts of the adhesive at aconvenient mix ratio. Some common mix ratios are 1:1, 2:1, 4:1 and 10:1,but preferably less than about 10:1 and more preferably less than about4:1.

Preferably, the mixed two-part compositions of the invention have asuitable viscosity to allow application without dripping. Preferably,the viscosities of the two individual components should be of the sameorder or magnitude. Preferably, the mixed compositions have theviscosity of about 100 (0.1 Pa·S) centipoise or greater, more preferablyabout 1,000 (1.0 Pa·S) centipoise or greater and most preferably about5,000 (5.0 Pa·S) centipoise or greater. Preferably the adhesivecompositions have a viscosity of about 150,000 (150 Pa·S) centipoise orless, more preferably about 100,000 (100 Pa·S) centipoise or less andmost preferably about 50,000 (50 Pa·S) centipoise or less.

Specific Embodiments

The following examples are included for illustrative purposes only andare not intended to limit the scope of the claims. Unless otherwisestated all parts and percentages are by weight.

Ingredients

The following ingredients were used in the examples providedhereinafter:

-   Methyl methacrylate—with 50 ppm MEHQ™ methoxyphenol supplied by Rohm    and Haas Company;-   HYPALON™ 20—chlorosulfonated chlorinated polyethylene, trademark of    DuPont; PARALOID™ BTA-753(ER)—methacrylate-butadiene-styrene    copolymer, trademark of Rohm and Haas Company;-   4-Methoxyphenol supplied by Aldrich Chemical Company, Inc.    Methacrylic Acid supplied by Aldrich Chemical Company, Inc.    4-Methoxyphenol supplied by Aldrich Chemical Company, Inc.

Two part formulations were prepared by mixing the ingredients for eachpart and then placed in separate containers. Several different part A(resin side) formulations were made.

Adhesive Preparation

All resin formulations were mixed using a dual asymmetric centrifugalFlackTek SpeedMixer™ DAC 400 FVZ by Hauschild Engineering. Thechlorinated polyethylene was combined with methyl methacrylate (MMA)into a preblend in a 40 percent chlorosulfonated chlorinatedpolyethylene to 60 percent MMA ratio using a roller mill. Thechlorinated chlorosulfonated polyethylene MMA preblend was added to aspeed mixing cup followed by methyl methacrylate and methoxyphenol(MEHQ™). The methacrylate-butadiene- styrene copolymer was then added tothe speed mixing cup and immediately incorporated with the otheringredients by hand using a tongue depressor. The speed mixing cup wasplaced into the speed mixer and mixed three times consecutively for oneminute at a speed of 1,800 rpm. The temperature of the sample waschecked after each mix using an infrared temperature probe and visuallyevaluated for homogeneity. If the sample was not visually homogeneous,additional one minute 1,800 rpm mixing cycles were utilized until visualhomogeneity was achieved. The temperature of each sample was kept below130° F. (54° C.) by letting the sample sit at room temperature betweenadditional mixes. After each sample was cooled to room temperature,methacrylic acid was charged into the speed mixing cup and immediatelyincorporated by hand using a tongue depressor. The speed mixing cup wasthen placed into the speed mixer and mixed twice for 1 minute at 1,800rpm.

Lap Shear Preparation

The substrates used in the lap shear construction were ED6100H E-Coatedcold rolled steel supplied by ACT Laboratories, Inc. and DLGF 9310.00ZBglass filled polypropylene supplied by The Dow Chemical Company. Eachsubstrate was cut into 1 inch×4 inch (2.54 cm×10.2 cm) strips. The ½inch (1.27 cm) bonding section of each strip was measured and marked.All resin formulations were combined with the hardener using a bagmixing technique. This bag mixing process was accomplished by adding thehardener then resin to a polyethylene bag in a one to one ratio byweight. The bag was sealed and mixed by hand using a rolling motion onthe palm of the hand to ensure an even mix was present. The corner ofthe bag was cut with scissors and the mixed adhesive was applied evenlyto one side of the pre-marked ½ inch (1.27 cm) portion of the 1 inch×4inch (2.54 cm×10.2 cm) substrate strips. To ensure consistent bondthickness 30 mil (0.76 mm) glass beads were applied to the adhesive andanother 1 inch×4 inch (2.54 cm×10.2 cm) substrate strip was laid on topto assemble the lap shear joint. The lap shears were held together withclips while curing for various times at room temperature.

Lap Shear Testing

The loads to failure of the lap shears were measured using an Instron®5500R Materials Testing System (Instron Corporation). Pneumatic gripswere used to hold the lap shear samples in place. The distance betweenthe grips was seven inches (17.8 cm). The crosshead speed was 0.5in./min (1.27 cm/min.). The computer measured the load as a function ofcrosshead displacement and loads were converted to pounds of force persquare inch of bond area. After each lap shear was tested to failure, afailure mode was assigned by visual evaluation. Failure modes wereclassified as Adhesive Failure AF, Cohesive Failure CF, Thin FilmCohesive Failure TFCF, Substrate Failure SUB, Surface Delamination SD,or E-coat Failure or voids V. If a mixed failure mode was present eachfailure mode was reported and a percentage estimate was assigned.

Part B comprised 65 percent methyl methacrylate, 25 percent ofmethacrylate-butadiene-styrene copolymer, 0.25 percent of IRGASTAB™FS301 FF which is IRGASTAB™ FS301 FF—a mixture of oxidized bis(hydrogenated tallow akyl) amines (IRGASTABTM FS042) and tris(2,4-di-tert-butyl phenol) phosphite trademark of Ciba SpecialtyChemicals and 10 parts of a complex of tri-n-butyl borane andmethoxypropyl amine. Several Part A formulations were prepared using theprocedures described above. The formulations are described below inTable 1.

The examples illustrate the strength development as a function of timeof alkylborane cured adhesive is dependent on chlorosulfonatedchloropolyethylene content. The data of Table 1 is compiled in a bargraph in FIG. 1.

TABLE 1 Example/Ingredients for Part A 1% 2% 3% 4% 5% MethylMethacrylate 64 58.8 56 54 44.5 Chlorosulfonated chlorinated 10 15.2 1820 29.5 polyethylene methacrylate-butadiene- 16.25 16.25 16.25 16.2516.25 styrene copolymer Methacrylic acid 9.5 9.5 9.5 9.5 9.5 Methylether of hydroquinone 0.25 0.25 0.25 0.25 0.25 Total 100 100 100 100 100Results of Lap Shear Testing 3 Hour Room Temperature 31 (0.21) 32 (0.22)23 (0.16) 35 (0.24) 71 (0.49) Cure E-Coat Substrate Lap CF CF CF CF CFShear psi/(MPa) failure mode 5 Hour Room Temperature 51 (0.35) 50 (0.34)55 (0.38) 81 (0.56) 223 (1.54) Cure E-Coat Substrate Lap 50% CF CF 25%CF 67% CF CF Shear psi/(MPa) failure mode 50% TFCF 75% TFCF 33% TFCF 24Hour Room Temperature 527 (3.63) 582 (4.01) 605 (4.17) 934 (6.44) 1027Cure E-Coat Substrate Lap CF CF 80% CF 77% (7.08) Shear psi/(MPa)failure mode 20% TFCF CF23% CF TFCF 24 Hour Room Temperature 699 (4.82)651 (4.49) 622 (4.29) 701 (4.83) 517 (3.56) Cure Polypropylene Substrate77% CF CF CF 40% CF 27% CF Lap Shear psi/(MPa) failure 23% SD 33% SUB73% AF mode 27% AF

1. A two part polymerizable composition comprising in one part anorganoboron compound capable of forming free radical generating speciesand in the second part one or more compounds capable of free radicalpolymerization and from about 20 to about 30 parts by weight based on100 parts by weight of the second part of i) a halogenated polyolefinhaving halosulfonyl groups or ii) a mixture of a halogenated polyolefinand an organic sulfonyl halide.
 2. A two part composition according toclaim 1 wherein the second part further contains a liberating compoundcapable of causing the organoboron compound to form free radicalgenerating species upon contacting the two parts.
 3. A two partcomposition according to claim 2 wherein the first part furthercomprises one or more compounds capable of free radical polymerization.4-5. (canceled)
 6. A two part composition according to claim 1 whereinthe organoboron compound is an organoborate, an organoborane aminecomplex or an amido-borate.
 7. A two part composition according to claim2 wherein the organoboron compound is an organoborate, an organoboraneamine complex or an amido organoborate.
 8. A two part compositionaccording to claim 1 wherein the weight of the halogen on thehalogenated polyolefin polymer is about 20 percent to about 45 percentbased on the weight of the halogenated polyolefin polymer.
 9. A two partcomposition according to claim 2 wherein the weight of the halogen onthe halogenated polyolefin polymer is about 20 to about 45 percent basedon the weight of the polyolefin polymer.
 10. A two part compositionaccording to claim 1 wherein the sulfonyl halide is present in an amountsufficient to provide about 0.01 to about 1.5 percent of sulfur based onthe weight of the halogenated polyolefin polymer.
 11. A two partcomposition according to claim 2 wherein the sulfonyl halide is presentin an amount sufficient to provide about 0.01 to about 1.5 percent ofsulfur based on the weight of the halogenated polyolefin polymer.
 12. Atwo part composition according to claim 1 wherein the halogen on thehalogenated polyolefin polymer is chloro or fluoro.
 13. A two partcomposition according to claim 2 wherein the halogen on the halogenatedpolyolefin polymer is chloro or fluoro. 14-15. (canceled)
 16. A two partcomposition according to claim 1 wherein the halogen on the sulfonylhalide is chloro.
 17. The two part composition according to claim 2wherein the halogen on the sulfonyl halide is chloro.
 18. A two partcomposition according to claim 1 wherein the halogenated polyolefin ischlorinated polyethylene.
 19. The two part composition according toclaim 2 wherein the halogenated polyolefin is chlorinated polyethylene.20. A two part composition according to claim 1 wherein the halogenatedpolyolefin is chlorinated polyethylene having sulfonyl chloride groups.21. The two part composition according to claim 2 wherein thehalogenated polyolefin is chlorinated polyethylene having sulfonylchloride groups.
 22. A method of polymerization comprising contactingthe components of the polymerizable composition of claim 1 underconditions such that the one or more compounds capable of free radicalpolymerization undergo polymerization.
 23. A method of claim 22 whichfurther comprises the step of heating the composition to an elevatedtemperature under conditions such that the compounds capable of freeradical polymerization undergo polymerization.
 24. A method ofpolymerization comprising contacting the components of the polymerizablecomposition of claim 2 under conditions such that the one or morecompounds capable of free radical polymerization undergo polymerization.25. A method of polymerization according to claim 24 wherein thecontacting occurs at, or near, ambient temperature.
 26. A method ofbonding two or more substrates together which comprises: contacting thecomponents of the composition of claim 1 together under conditions suchthat polymerization is initiated; contacting the adhesive compositionwith the two or more substrates; positioning the two or more substratessuch that the adhesive composition is located between the two or moresubstrates wherein they are in contact with one another; and allowingthe adhesive to cure so as to bind the two or more substrates together.27. A method of bonding two or more substrates according to claim 26which further comprises heating the adhesive composition to atemperature such that organoboron compound to form free radicalgenerating species.
 28. A method of bonding two or more substratestogether which comprises: contacting the components of the compositionof claim 2 together under conditions such that polymerization isinitiated; contacting the adhesive composition with the two or moresubstrates; positioning the two or more substrates such that theadhesive composition is located between the two or more substrateswherein they are in contact with one another; and allowing the adhesiveto cure so as to bind the two or more substrates together. 29-33.(canceled)